Java Class Load loadClass(String className, Class type)

Description

Load a class of a particular type.

License

Open Source License

Parameter

Parameter	Description
T	the desired interface type
className	the class name that implements the interface
type	the desired interface

Return

the class

Declaration

public static <T> Class<? extends T> loadClass(String className, Class<T> type) 

Method Source Code

//package com.java2s;
/* ===================================================================
 * ClassUtils.java/* www .ja va  2  s.  co  m*/
 * 
 * Created Jul 15, 2008 8:20:38 AM
 * 
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of 
 * the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful, 
 * but WITHOUT ANY WARRANTY; without even the implied warranty of 
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 
 * 02111-1307 USA
 * ===================================================================
 * $Id$
 * ===================================================================
 */

public class Main {
    /**
     * Load a class of a particular type.
     * 
     * <p>This uses the {@code type}'s ClassLoader to load the class. If that is 
     * not available, it will use the current thread's context class loader.</p>
     * 
     * @param <T> the desired interface type
     * @param className the class name that implements the interface
     * @param type the desired interface
     * @return the class
     */
    public static <T> Class<? extends T> loadClass(String className, Class<T> type) {
        try {
            ClassLoader loader = type.getClassLoader();
            if (loader == null) {
                loader = Thread.currentThread().getContextClassLoader();
            }
            Class<?> clazz = loader.loadClass(className);
            if (!type.isAssignableFrom(clazz)) {
                throw new RuntimeException("Class [" + clazz + "] is not a [" + type + ']');
            }
            return clazz.asSubclass(type);
        } catch (ClassNotFoundException e) {
            throw new RuntimeException("Unable to load class [" + className + ']', e);
        }
    }
}

Related

1. loadClass(String classname, Class clazz)
2. loadClass(String classname, Class clazz)
3. loadClass(String className, Class context, boolean checkParent)
4. loadClass(String className, Class ofType)
5. loadClass(String className, Class targetType, ClassLoader cl)
6. loadClass(String className, ClassLoader cl)
7. loadClass(String className, ClassLoader classLoader)
8. loadClass(String className, ClassLoader classLoader)
9. loadClass(String className, ClassLoader classLoader)